1. Field of the Invention
The present invention relates to a monitoring system which monitors occurrence of a nonstationary state by a central processing device and a terminal, and more particularly, the present invention relates to a monitoring system suitable for preventing crime in a residence.
2. Description of the Related Art
In recent years, in order to cope with an increasing number of property crimes, a demand for systems which monitor residences has increased. A conventional monitoring system for monitoring burglary or the like is constituted by a combination of a plurality of sensor terminals for detecting a burglar and a central processing device for issuing a warning.
For example, a monitoring system disclosed in U.S. Pat. No. 5,920,270 has a plurality of sensor terminals and a residence information board. The monitoring system is designed such that when a sensor terminal detects the burglary, a warning is generated from a loudspeaker arranged on the residence information board.
In another monitoring system disclosed in U.S. Pat. No. 5,461,365, when a terminal held by a user detects an occurrence of an emergency situation, the information of the emergency situation is transmitted to a central processing device by air, and a warning is generated from the central processing device.
In still another monitoring system disclosed in Japanese Patent Laid-Open Publication No. 2002-16715, an information terminal held by a user and a monitoring unit (imaging device) serving as a central processing device can be communicated, and the system has a function of monitoring a state of a place near the monitoring unit and has a function to output the sound which is transmitted from the information terminal and amplified.
In the monitoring system disclosed in U.S. Pat. No. 5,920,270, a place where warning sound is generated corresponds to the position of a central processing device serving as a residence information board, and is not a position where a terminal is installed and where the burglary occurs. Thus, the threatening effect to the burglar is insufficient.
In the monitoring system disclosed in U.S. Pat. No. 5,461,365, when an emergency situation occurs, it can be checked at only a position where the central processing device is installed whether the information of the emergency situation is accurately accepted by a receiver around the central processing device. A user cannot easily recognize that the information is accurately accepted at the position where the user transmits a signal.
According to the monitoring system described in Japanese Patent Laying-Open Publication No. 2002-16715, for example, it is difficult to monitor the sound or voice of burglary or threaten the burglar when the burglary occurs at a place distant from a place where the monitoring unit serving as a central processing device is disposed.